Russell Brand's future in-laws believe that he's on his way to becoming "a great man of God", Katy Perry has revealed.

Katy, 25, said her devout Christian parents think her fiance, a former sex addict who had an 11-year drug habit, is going through a religious "transition".

The singer told the Radio Times she is also convinced that the 35-year-old is having a spiritual awakening.

The I Kissed A Girl star, whose father is a minister, said: "My parents always give people the benefit of the doubt and it's up to the person to mess it up."

Katy said: "My mum has this idea about Russell that he's going to be a great man of God and his transition is happening.

"I think it is happening in some way, but won't be exactly specific to what my parents think.

"Can you imagine where he's come from to where he is now? There's got to be a reason why he's arrived at all. My mum is always saying there is a purpose to your life. I'm all into the search. One day I'm going to get out there and ask questions like I did when I was 10."

She said of her future husband: "He's a genius and geniuses are both wonderful and delicate in the greatest way."

Katy admitted she could not sleep with the lights off unless Russell was with her, saying: "I don't like sleeping in the dark. I sleep with lights on unless I'm with Russell. I think a lot of evil things go on in the dark."

She said: "I still have to cover my toes because I'm like that kid who thinks there's a witch under my bed who's going to eat my tootsies off. I have nightmares. Russell is my dreamcatcher."